We question whether the increasingly popular, radical idea of turning half the earth into a network of protected areas is either feasible or just. We argue that this 'half earth' plan would have widespread negative consequences for human populations and would not meet its conservation objectives. It offers no agenda for managing biodiversity within a 'human half' of Earth. We call instead for alternative radical action that is both more effective and more equitable, focused directly on the main drivers of biodiversity loss by shifting the global economy from its current foundation in growth while simultaneously redressing inequality.
Main TextThere is a new call to extend conservation frontiers as an ultimate attempt to save global biodiversity. Under the slogan 'nature needs half' (http://natureneedshalf.org/) and spearheaded by leading conservation scientists such as Edward O. Wilson (2016), Reed Noss (Noss et al, 2012), George Wuerthner and John Terborgh (Wuerthner et al, 2015), a vision has been formulated to turn half of the earth into a series of interconnected protected areas. This radical plan for conservation seeks to expand and strengthen the world's current network of protected areas to create a patchwork grid of reserves encompassing at least half the world's surface and hence "about 85 percent" of remaining biodiversity (Wilson, 2016). We wish to open up debate about this idea. While it might be interpreted as simply a rhetorical challenge to provoke greater conservation effort, it is proposed by senior scientific figures and is being widely discussed and supported. Critical reflection about this proposal is thus important.The plan proposed is staggering in scale: protected areas, according to the IUCN, currently incorporate around 15.4% of the earth's terrestrial areas and 3.4% of its oceans. They would thus need to more than triple in extent on land and by more than ten-fold in the oceans. Not only would this include the earth's currently still relatively intact ecosystems and natural habitats, it would also necessarily entail an active programme of restoration and 'rewilding' to 2 return larger areas to a more pristine 'pre-human' baseline (Wilson, 2016;Noss et al, 2012;Donlan et al, 2005). E. O. Wilson is arguably most explicit in his recent book Half-Earth, stating that "only by setting aside half the planet in reserve, or more, can we save the living part of the environment and achieve the stabilization required for our own survival" (Wilson, 2016: 3).Other conservationists agree that such a goal is the 'only defensible target' from a 'strictly scientific point of view' to allow for a sustainable future (Wuerthner et al, 2015: 18).These proposals seem to be driven by the credo 'desperate times call for desperate measures'. We agree with Wilson and other conservationists that because biodiversity is being lost at an unprecedented rate as a result of human activity therefore urgent need for action to address this. Desperate times, however, demand careful decisions. We argue that the 'hal...